Continuous automatic coker



Jufiy 7, 11959 P. ALSPAUGH CONTINUOUS AUTOMATIC (JOKER Filed Dec. 9. 1954 INVENTOR PAU L L. ALSPAUGH ATTORNEY (IONTINUOUS AUTDMATIC COKER Paul L. Alspaugh, South Charleston, W. Va., assignor to gnion Carbide Corporation, a corporation of New ork Application December 9, 1954, Serial No. 474,147

'10 Claims. (Cl. 202--22) of these however have proved entirely satisfactory and efficient. Most coke from liquid materials today is still made by heating the material in large batch vessels and then breaking out the coke manually or mechanically. The continued use of this wasteful and ineflicient method is primarily caused by the difliculties inherent in any methodof handling molten pitch, large masses of solid coke and similar materials. The hardening of the pitch to the coke stage is quite diflicult to control and the abrasive as well as gumming nature of these materials make the design of suitable machinery a perplexing problem.

It is an object of this invention to provide a method and apparatus whereby coke may be continuously produced from a liquid or semi-liquid pitch or similar material. It is a further object of the invention to provide a method and apparatus whereby the production of coke is relatively automatic and requires only nominal attention and control by anoperator. Yet another object of the invention is top roduce coke of a high quality, suitable for electrodes and analogous uses. Still further it is an object of the invention to provide a continuouscooking process wherein the volatile materials driven off during coking are recovered for utilization.

We have discovered a method and apparatus for continuously producing coke from pitch and similar materials which satisfies fully the aforementioned objects and which has other advantages which will be apparent from the detailed description which follows.

Basically, coke is produced by heating a suitable carbonaceous material, such as pitch or petroleum residues, at such temperatures that the volatile materials are driven off and coke is formed by polymerization and hardening of the material. Polymerization and coking take place best with respect to process conditions at temperatures of 400 to 600 C. The change is a gradual one with the liquid material becoming more and moreviscous. and gradually hardening as the material is held at such temperatures, and may require from 1 to 6 hours of continued treatment. T hetime for full coking will of course vary with the temperatures employed and to some extent with the nature of the material being converted.

Because the coking process is a slow and gradual one it is difiicult to control. It isvery difficult to maintain a uniform temperature throughout the entire mass of material being coked and hence that portion nearest the heat source tends to coke more rapidly than the rest. When the material is merely coked in a stationary vat this fact is of little consequence, but when a continuous process,

2,893,922 Patented July 7, 1959 involving movement of .the material being coked is de sired, it presents definite difliculties and complications. The materials tend to coke and accumulate on the heated surfaces and thus to impede the movement of the material. A further result may be that a layer of coke adjacent to the surface of the coker will reduce heat transfer and cool the coke thereby preventing full coking of the main body of the materiali These problems occur not only during the actual coking but all the While the liquid material is being held and fed into the coker. All orifices and openings are subject to plugging and fouling from accumulated coke.

According to the method of our invention, a stream of molten feed of pitch or pitch-like material at a temperature of 400 to 600 C. is fed into a coking apparatus where it becomes part of a pool of semi-polymerized material. The pitch is maintained there at a temperature of 400 to 600 C. and as polymerization and hence viscosity increase the material is picked up by a conveyor system which is constantly moving through the pool. The conveyor system is such that only that portion of the .material which has reached a pre-determined degree of polymerization and viscosity will be picked up and carried out of the pool; any other material will flow back into the pool to be further polymerized. The material which has been picked .up is moved slowly through a coking zone where the temperature is maintained and final and full polymerization occurs. Upon leaving the coking zone the fully polymerized coke is automatically discharged by the conveyor system as product. The gases liberated during the coking are recovered and their valuable constituents isolated.

Preferably, the molten pitch used as starting material comes directly from its source in the molten state. However the method of the invention is of course equally effective when solidified pitch material is melted and fed into apparatus. The pitch should be fed into the coking apparatus at a temperature within the range of the operating temperature for coking, that is, at a temperature between 400 and 600C. If necessary, the pitch may be adjusted to this temperature in any suitable heating apparatus. In our operation ofthe invention cold granulated pitch was used as the original starting materialand was first heated in a simple electrically heated vessel equipped with a stirringpaddle. Final adjustment of the temperature of the molten pitch was made in an agitated heating vessel of the type shown in the drawing. This heating vessel is not an essential part of the invention, however, and would not be necessary if molten pitch were available at the desired operating temperature.

The coking unit is a partially enclosed conveyor means comprising a conveyor chain or like device. The unit is preferably at an angle with the horizontal and both sides of the chain are in the vertical plane, with the lower side moving upward. The angle of elevation need not be great and may be as little as 1 degree with the horizontal. One embodimentof the conveyor means, the embodiment shown in the drawing, is a series of scraper flights mounted on an endless chain. The lower end of the chain passes around an idler sprocket and is partially submerged in a pool of partially polymerized material which has come from the heater unit. The scraper flights are circular and the bottom of the enclosing casing is rounded to conform to the shape of the flights so that there is mechanical entrapment of the closing casing, which is heated throughout its length to prevent heat loss, ends. At this point provision is made to receive the finished coke falling from the flights. A mechanical device is used at this point to assist in removing the coke from the conveyor flights. Above point the conveyor system returns around a sprocket. This may be powered to turn the conveyor system or it may be an idler and the power applied to the system below the sprocket. At the points where the conveyor enters and leaves the enclosed coking apparatus casing a suitable seal is provided and a duct system conveys the volatile vapors removed through a vapor outlet from the conveyor casing to a recovery unit.

In the drawing:

Fig. l is a sectional view of one embodiment of the invention, showing a heater unit A and a coking unit B.

Fig. 2 is a sectional view through the conveyor system, showing details of the flights and shell structure.

Fig. 3 is a detail view of the coke removal apparatus.

The molten pitch or other material enters the shell 11 of the heater unit A through the inlet pipe 12. It moves upward in the annular space 13 between shell 11 and the inner wall 14. The material then flows over the top of the inner wall 14 and into the funnel collector 15, from which it flows into the discharge pipe 16. Clogging and agglomeration of coke within this unit is prevented by rotating scraper blades. The outer scraper blade 17 is attached to the blade support 19 which is aflixed through the blade support hub 20 to the rotating shaft 21. The shaft 21 is supported by bearings 22 and powered through sprocket 23 from a variable motor and speed reduction unit, the shaft 21 passing down through the heater unit top 25. A drain 26 for the unit is provided. Heat is supplied to the heater unit by a heating means comprising a plurality of electrical resistance strip heaters 27 which are positioned on the surface of both the outer shell 11 and the inner side of the inner wall 14, which side is not in contact with the pitch.

After being heated to the desired viscosity and degree of partial polymerization the pitch enters the continuous coking unit B at the inlet end through the inlet pipe 30. It flows into the pool of partially polymerized pitch 31 which is contained by the outer casing 32 of the coker. Pitch is dragged up the bottom wall of the casing 32 of the inclined coker unit B by the circular flights 33 mounted on the endless chain 34, which constitutes the conveyor means of the embodiment shown. The bottom inner surface of the coker casing 32 is shaped to conform to the circumference of the lower part of the conveyor flights. The chain 34 with its attached flights 33 travels in the direction indicated in the drawing around the tail idler sprocket 35 and the head sprocket 36. In the embodiment shown in the drawing the head sprocket 36 is'an idler and the chain is powered through the gear drive 37. If desired, however, power could be supplied through the sprocket 36. During their return to the pitch pool the flights 33 and chain 34 are supported by the support rails 38 which are attached to the coker casing 32 by brackets 39. As the loaded flights leave the enclosed coker casing 32 they are aligned by guide rails 40 attached to the casing 32 by brackets 41. Restricted openings 42 at the upper end of the casing 32 conform to the size and shape of the circumference of the flights 33 and thus prevent the escape of the volatile constituents which are driven off during coking. These volatile constituents are collected by the hood 43 covering the vapor outlet in the top of the casing 32 and are carried away by the duct 44 for recovery elsewhere.

As the coke laden flights arrive at the outlet end of the coker and the discharge point 48 the coke is removed by a coke removal means comprising in the embodiment shown a coke removal head 49 shaped to fit around the chain 34 which head is attached to a support bar 50. Figure 3 of the drawing clarifies the arrangement of this apparatus. The support bar 50 is attached to two pistons 51 which in the embodiment shown are powered by air. cylinders 52. The air cylinders 52 are mounted on cross beams 56 which are secured to supporting beams 53 based on the floor or ground beneath the coking unit. The coke removal unit is further braced by braces 54 between the supporting beams 53 and the outer casing 32 of the coking unit. The rest position of the support bar 50 and the attached coke removal head 49 is between the upper and lower halves of the chain 34, and the air cylinders 52 and pistons 51 are so positioned on either side of the chain 34 and flights 33 that there is no contact at any time between these parts. When a flight 33 arrives at the discharge point 48, the air cylinders are operated to force the pistons in a downward direction. This causes the coke removal head 49 to move down just in front of the coke laden scraper flight 33 until the apex of the opening in the coke removal head 49 is just above the chain 34. This action of the coke removal head 49 dislodges the coke from the scraper flight 33 and the chain 34. The loosened coke then falls downward into the collecting funnel 46 provided for this purpose, and is removed from the system as product. The cycle of operation of the air cylinders 52 is e1ectrically controlled with respect to the speed of the chain 34 so as to cause the coke removal head 49 to move downward just as each coke laden flight 33 arrives at the discharge point 48. Hydraulic cylinders can be used in place of the air cylinders shown or the coke removal may be accomplished by any other suitable means.

The coker is supported at intervals along its length by pillars 45 and suitable supports are provided for the heating unit A and the head sprocket and drive unit of the coker. Electrical resistance strip heaters 47 are provided along the length of the coker unit casing 32, whereby the amount of heat supplied at any point can be varied readily depending on the material being coked and other conditions aifecting heat loss.

As stated earlier, the molten pitch enters the coking unit at a temperature within the coking temperature range of 400 to 600 C. As the conveyor flights 33 move slowly through the coker unit each drags with it a portion of the most fully polymerized material from the pitch pool and the polymerization of the material to coke continues as the volatile constituents are driven off. For this polymerization to occur it is ordinarily necessary only to maintain the pitch at the coking temperature at which it entered the coking unit, andhence the conditions within the unit are essentially adiabatic, with at most a small quantity of additional heat being necessary for some materials. Thus ordinarily only a much heat need be applied through the electrical strip heaters 47 as is necessary to compensate for heat loss so as to maintain the temperature of the material on the flights 33 at coking temperature.

The invention has been illustrated in the drawing with a coking unit using a series of circular flights on a single chain to move the pitch through the unit and electrical strip heaters to maintain a coking temperature. The invention is in no sense limited to such specific types of apparatus, however, and numerous other embodiments are possible within the scope of the invention. Instead of the electrical strip heaters illustrated, any controllable heat source could be used, capable of maintaining a temperature of 400 to 600 C. within the coker, for instance gas heaters. The conveyor device is not limited to circular chain flights or even to chain flights. Any conveyor system which would scoop the material from the pitch pool, moves it through the coking zone in a manner which prevents the build-up of solid coke on the walls of the coker casing within the coking zone, and discharge the coke at the outlet end of the coker would be suitable. For instance, larger scraper flights, rectangular in shape and pulled by a plurality of chain could be used. The heater unit A is subject to modification also, the requirement being only that it heat the material which is to be cokecl to the temperature necessary to give the desired degree of partial polymerization and viscosity.

In our operation of the invention we have found that preferably the pitch is introduced into the coker at a temperature of 400 to 500 C. and an approximate viscosity of 300 to 100,000 centipoises. Using scraper flights the coker is preferably tilted upward at an angle of l to degrees with the horizontal. At the lower or inlet end of the coker unit where the pitch pool is formed a temperature of 400 to 500 C. is preferably maintained. With the proper incline of the coker unit and the proper temperature maintained in the pitch pool the operation of the unit will be such that the scraper flights will pull out of the pitch pool only that portion of the pitch which has been polymerized sufliciently to have a high enough viscosity to be trapped by the flights. That portion of the material in the pool which has not been sufficiently polymerized will be so relatively low in viscosity that it will run back into the pool to then the further polymerized. Thus the invention assures that only material which is ready by way of sufficient partial polymerization will be drawn through the final coking zone and there is no danger of not producing fully coked product.

The speed of the conveyor system through the coking zone is quite slow, being measured in feet per hour. The specific speed used will depend on the length of the coking zone and may vary to some extent with the nature of the material being coked. Ordinarily, the material will 'be moving through the coking zone for a period of from one to six hours.

A run with the apparatus of the invention was made in the following manner. Pitch having a softening point of 190 C. and a chemical analyses as given below was fed into the apparatus at the rate of 75 pounds per hour. The pitch entered the heating unit A at a temperature of 300 C. and was discharged from there into the coking unit B at a temperature of 450 C. The temperature of the pitch pool at the bottom of the coking unit and at the walls of the coking unit was maintained at 460 C. throughout the run. The chain and scraper flights moved through the coking unit at a speed of 6 to 20 feet per hour. The coke product had an apparent density of 60 pounds per cubic foot and contained 9% volatile manner at l000 C. The coke product comprised 80% by weight of the total reaction product of the coking process on a material balance basis, with respect to the weight of pitch fed into the apparatus. The remainder consisted of 12% oil, 5% gas and 3% water and waste. The chemical analyses of the pitch feed and coke produced were as follows:

The method and apparatus of the invention can be used with many different types of pitch and pitch-like materials. The quality of the coke produced will of course depend on the type of material used. A distinct advantage of the invention is that when high quality pitch is used as the starting material, coke of high quality can be produced which is suitable for graphite electrodes and other high quality applications. This is evident from the results of tests made on graphite electrodes manufactured from coke produced by the invention. Three samples of coke from the invention were tested and the coke gave an average yield upon calcination of 91.0 percent. Electrodes made from each of the three samples had an average apparent density of 1.47, an average specific resistance in micro ohms per inch of 385 and an average coefiicient of expansion of 8.8x 10* inches per inch per degree centigrade.

What is claimed is:

l. A method for continuously coking pitch-like material which comprises maintaining a pool of molten pitch at a coking temperature, said pool having a free surface continuously introducing molten pitch into said pool, continuously removing from below said free surface of said pool by mechanical entrapment all solids formed in said pool and that portion of said molten pitch which have descended below said free surface by the action of gravity on the polymerized particles which have increased in weight during their partial polymerization, and simultaneously progressing said removed solids and partially polymerized pitch along an upwardly inclined path, while permitting the unpolymerized liquid to flow back into said pool, said upwardly inclined path being through an additional coking zone wherein said partially polymerized pitch is fully coked, and continuously discharging fully polymerized pitch from said additional coking zone as coke product.

2. An apparatus for continuously producing coke from pitch-like material which comprises an elongated inclined enclosed coking vessel; an inlet positioned at the lower end of said inclined vessel for receiving hot molten pitch material to maintain in said lower end a pool'of molten pitch having a free surface; a coke outlet for coke product positioned at the higher end of said inclined vessel; a vapor outlet; conveyor means in scraping relationship with the bottom interior surface of said vessel below said free surface of said pool of molten pitch and extending from below said free surface of said pool of molten pitch and along the length of the interior of said inclined vessel and out through said coke outlet, a portion of said conveyor means contacting the bottom and lower walls of said interior of said vessel and said conveyor means serving to collect solids and partially polymerized pitch material from below said free surface of said pool of molten pitch in said inlet end of said inclined vessel, whereby said partially polymerized pitch material is fully polymerized to form coke, and to discharge said coke through said coke outlet as product; heating means positioned along the length of said inclined vessel for maintaining said pitch material at coking temperature for the duration of its stay in said vessel; and coke removal means positioned at said coke outlet of said vessel and adapted to dislodge coke product from said conveyor means as said conveyor means discharges coke product through said coke outlet.

3. An apparatus for continuously producing coke from pitch-like material which comprises an elongated inclined enclosed coking vessel; an inlet positioned at the lower end of said inclined vessel for receiving hot molten pitch material to maintain in said lower end a pool of molten pitch having a free surface; a coke outlet for coke product positioned at the higher end of said inclined vessel; a vapor outlet; conveyor means extending from below said free surface of said pool of molten pitch and along the length of the interior of said inclined vessel and out through said who outlet, said conveyor means comprising a moving chain-type mechanism having a plurality of scraper flights attached thereto and cooperating with the bottom interior surface of said conveyor vessel in scraping relationship with said interior surface of said vessel below said free surface of said pool of molten pitch, said interior surface being shaped to conform to the shape of the lower periphery of said scraper flights, and said conveyor means serving to collect solids and partially polymerized pitch material from below said free surface of said pool of molten pitch in said inlet end of said inclined vessel and to slowly move said material through the length of said vessel, said scraper flights in moving up through said inclined vessel permitting the unpolymerized pitch material to overflow from an upper flight to a lower flight and thus back to said pool, whereby said partially polymerized pitch material is fully polymerized to form coke, and to discharge said coke through said coke outlet as product; heatingmeans positioned .along the length of said inclined vessel for maintaining said pitch material at coking temperature for the duration of its stay in said vessel; and coke removal means positioned at said coke outlet of said inclined vessel and adapted to dislodge coke product from said conveyor means as said conveyor means discharges coke product through said coke outlet.

4. An apparatus for continuously producing coke from pitch-like material which comprises an elongated inclined enclosed coking vessel; an inlet positioned at the lower end of said inclined vessel for receiving hot molten pitch material to maintain in said lower end a pool of molten pitch having a free surface; a coke outlet for coke product positioned at the higher end of said inclined vessel; a vapor outlet; conveyor means extending from below said free surface of said pool of molten pitch and along the length of the interior of said inclined vessel and out through said coke outlet, said conveyor means comprising a single moving chain having a plurality of scraper flights positioned along the length thereof and cooperating with the bottom interior surface of said conveyor vessel in scraping relationship with said interior surface of said vessel below said free surface of said pool of molten pitch, said interior surface being shaped to conform to the shape of the lower periphery of said scraper flights, and said conveyor means serving to collect solids and partially polymerized pitch material from below said free surface of said pool of molten pitch in said inlet end of said inclined vessel and to slowly move said material through the length of said inclined vessel, said scraper flights in moving up through said inclined vessel permitting the unpolymerized pitch material to overflow from an upper flight to a lower flight and thus back to said pool, whereby said partially polymerized pitch material is fully polymerized to form coke, and to discharge said coke through said coke outlet as product; heating means positioned along the length of said inclined vessel for maintaining said pitch material at coking temperature for the duration of its stay in said vessel; and coke removal means positioned at said coke outlet of said inclined vessel and adapted to dislodge coke product from said conveyor means as said conveyor means discharges coke product through said coke outlet.

5. An apparatus for continuously producing coke from pitch-like material which comprises an elongated inclined enclosed coking vessel; an inlet positioned at the lower end of said inclined vessel for receiving hot molten pitch material to maintain in said lower end a pool of molten pitch having a free surface; a coke outlet for coke product positioned at the higher end of said inclined vessel; a vapor outlet; conveyor means extending from below said free surface of said pool of molten pitch and along the length of the interior of said inclined vessel and out through said coke outlet, said conveyor means comprising a plurality of scraper flights, each of said flights'being attached to a plurality of parallel moving chains, said flights being positioned along the length of said chains and said flights cooperating with the bottom interior surface of said conveyor vessel in scraping relationship with said interior surface of said vessel below said free surface of said pool of molten pitch, said interior surface being shaped to conform to the shape of the lower periphery of said scraper flights, and said conveyor means serving to collect solids and partially polymerized pitch material from below said free surface of said pool of molten pitch in said inlet end of said inclined vessel and to slowly move said material through the length of said inclined vessel, said scraper flights in moving up through said inclined vessel permitting the unpolymerized pitch material to overflow from an upper flight to a lower flight and thus back to said pool, whereby said partially polymerized pitch material is fully polymerized to form coke, and to discharge said coke through said coke outlet as product; heating means positioned along the length of said inclined vessel for maintaining said pitch material at coking temperature for the duration of its stay in said conveyor means discharges coke product through said coke outlet;

'6. An apparatus for continuously producing coke from pitch-like material which comprises an elongated inclined enclosed coking vessel; an inlet positioned at the lower end of said inclined vessel for receiving hot molten pitch material to maintain in said lower end a pool of molten pitch having a free surface; a coke outlet for coke product positioned at the higher end of said inclined vessel; a vapor outlet; conveyor means in scraping relationship with the bottom interior surface of said vessel below said free surface of said pool of molten pitch and extending from below said free surface of said pool of molten pitch and along the length of the interior of said inclined vessel and out through said coke outlet, a portion of said conveyor means contacting the bottom and lower walls of 'said interior of said vessel and said conveyor means serving to collect solids and partially polymerized pitch material from below said free surface of said pool of molten pitch in said inlet end of said inclined vessel and to slowly move said material through the length of said vessel, whereby said partially polymerized pitch material is fully polymerized to form coke, and to discharge said coke through said coke outlet as product; a plurality of electrical resistance heaters positioned along the length of said inclined vessel for maintaining said pitch material at coking temperature for the duration of its stay in said inclined vessel; and coke removal means positioned at said coke outlet of said inclined vessel and adapted to disclodge coke product from said conveyor means as said conveyor means discharges coke product through said coke outlet.

7. An apparatus for continuously producing coke from pitch-like material which comprises an elongated inclined enclosed coking vessel; an inlet positioned at the lower end of said inclined vessel for receiving hot molten pitch material to maintain in said lower end a pool of molten pitch having a free surface; a coke outlet for coke product positioned at the higher end of said inclined vessel; a vapor outlet; conveyor means in scraping relationship with the bottom interior surface of said vessel below said free surface of said pool of molten pitch and extending from below said free surface of said pool of molten pitch and along the length of the interior of said inclined vessel and out through said coke outlet, a portion of said conveyor means contacting the bottom and lower walls of said interior of said vessel and said conveyor means serving to collect solids and partially polymerized pitch material from below said free surface of said pool of molten pitch in said inlet end of said inclined vessel and to slowly move said material through the length of said inclined vessel, whereby said partially polymerized pitch material is fully polymerized to form coke, and to dis charge said coke through said coke outlet as product; a plurality of gas jets positioned along the length of said inclined vessel for maintaining said pitch material at coking temperature for the duration of its stay in said vessel; and coke removal means positioned at said coke outlet of said inclined vessel and adapted to dislodge coke product from said conveyor means as said conveyor means discharge coke product through said coke outlet.

8. An apparatus for continuously producing coke from pitch-like material which comprises an elongated inclined enclosed coking vessel; an inlet positioned at the lower end of said inclined vessel for receiving hot molten pitch material to maintain in said lower end a pool of molten pitch having a free surface; a coke outlet for coke product positioned at the higher end of said inclined vessel; a vapor outlet; conveyor means extending from below said free surface of said pool of molten pitch and along the length of the interior of said inclined vessel and out through said coke outlet, said conveyor means comprising a moving chain-type mechanism having a plurality of scraper flights attached thereto and cooperating with the bottom interior surface of said conveyor vessel in scraping relationship with said interior surface of said vessel below said free surface of said pool of molten pitch, said interior surface being shaped to conform to the shape of the lower periphery of said scraper flights, and said conveyor means serving to collect solids and partially polymerized pitch material from below said free surface of said pool of molten pitch in said inlet end of said inclined vessel and to slowly move said material through the length of said inclined vessel, said scraper flights in moving up through said inclined vessel permitting the unpolymerized pitch material to overflow from an upper flight to a lower flight and thus back to said pool, whereby said partially polymerized pitch material is fully polymerized to form coke, and to discharge said coke through said coke outlet as product; heating means positioned throughout the length of said inclined vessel for the purpose of maintaining said pitch material at coking temperature for the duration of its stay in said coking vessel; and coke removal means positioned at said coke outlet of said inclined vessel comprising a coke removal head so powered as to be capable of moving across the face of said scraper flights and thereby dislodging coke from the face of said scraper flights at said coke outlet of said vessel, the movement of said head being synchronized with the movement of said moving chain-type mechanism and said scraper flights attached thereto.

9. An apparatus for continuously producing coke from pitch-like material which comprises an elongated inclined enclosed coking vessel; an inlet positioned at the lower end of said inclined vessel for receiving hot molten pitch material to maintain in said lower end a pool of molten pitch having a free surface; a coke outlet for coke product positioned at the higher end of said inclined vessel; a vapor outlet; conveyor means extending from below said free surface of said pool of molten pitch and along the length of the interior of said inclined vessel and out through said coke outlet, said conveyor means compris ing a moving chain-type mechanism having a plurality of scraper flights attached thereto and cooperating with the bottom interior surface of said conveyor vessel in scraping relationship with said interior surface of said vessel ibelow said free surface of said pool of molten pitch, said interior surface being shaped to conform to the shape of the lower periphery of said scraper flights, and said conveyor means serving to collect solids and partially polymerized pitch material from below said free surface of said pool of molten pitch in said inlet end of said inclined vessel and to slowly move said material through the length of said inclined vessel, said scraper flights in moving up through said inclined vessel permitting the unpolymerized pitch material to overflow from an upper flight to a lower flight and thus back to said pool, whereby said partially polymerized pitch material is fully polymerized to form coke, and to discharge said coke through said coke outlet as product; heating means positioned throughout the length of said inclined vessel for the purpose of maintaining said pitch material at coking temperature for the duration of its stay in said coking vessel; and coke removal means positioned at said coke outlet of said inclined vessel comprising a coke removal head so powered by pistons operated by compressed air cylinders as to be capable of moving across the face of said scraper flights and thereby dislodging coke from the face of said scraper flights at said coke outlet of said vessel, the movement of said head being synchronized with the movement of said moving chaintype mechanism and said scraper flights attached thereto.

10. An apparatus for continuously producing coke from pitch-like material which comprises an elongated inclined enclosed coking vessel; an inlet positioned at the lower end of said inclined vessel for receiving hot molten pitch material to maintain in said lower end a pool of molten pitch having a free surface; a coke outlet for coke product positioned at the higher end of said inclined vessel; a vapor outlet; conveyor means extending from below said free surface of said pool of molten pitch and along the length of the interior of said inclined vessel and out through said coke outlet, said conveyor means comprising a moving chain-type mechanism having a plurality of scraper flights attached thereto and cooperating with the bottom interior surface of said conveyor vessel in scraping relationship with said interior surface of said vessel below said free surface of said pool of molten pitch, said interior surface being shaped to conform to the shape of the lower periphery of said scraper flights, and said conveyor means serving to collect solids and partially polymerized pitch material from below said free surface of said pool of molten pitch in said inlet end of said inclined vessel and to slowly move said material through the length of said inclined vessel, said scraper flights in moving up through said inclined vessel permitting the unpolymerized pitch material to overflow from an upper flight to a lower flight and thus back to said pool, whereby said partially polymerized pitch material is fully polymerized to form coke, and to discharge said coke through said coke outlet as product; heating means positioned throughout the length of said inclined vessel for the purpose of maintaining said pitch material at coking temperature for the duration of its stay in said coking vessel; and coke removal means positioned at said coke outlet of said inclined vessel comprising a coke removal head so powered by pistons operated by hydraulic cylinders as to be capable of moving across the face of said scraper flight and thereby dislodging coke from the face of said scraper flights at said coke outlet of said inclined vessel, the movement of said head being synchronized with the movement of said moving chaintype mechanism and said scraper flights attached thereto.

References Cited in the file of this patent UNITED STATES PATENTS 1,573,824 Grifliths Feb. 23, 1926 1,931,594 Weaver Oct. 24, 1933 2,125,897 Michot-Dupont Aug. 9, 1938 2,179,080 Alther Nov. 7, 1939 2,697,069 Bradley Dec. 14. 1954 FOREIGN PATENTS 378,848 Great Britain Aug. 16, 1932 UNITED STATES PATENT oTTTcE @ERTTMQATE 0F CGRRIEQ'HQN Patent N00 2,893,922 July '7, 1959 Paul L Alspaugn It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 42 for "top reduce" read we to produce line 44 for "cooking" read coking column 5, in the table, under the headin "Coke Produced", last line thereof, total of the column; for "00000" read me 100,00 column 8 line 2'7, before "vessel" insert inclined line 35, for "disolodge" read dislodge e Signed and sealed this 9th day of February 1960 (SEAL) Attest:

KARL Ho AXLINE RUBERT C. WATSON Commissioner of Patents Attesting Ufiicer 

1. A METHOD FOR CONTINUOUSLY COKING PITCH-LIKE MATERIAL WHICH COMPRISES MAINTAINING A POOL OF MOLTEN PITCH AT A COOKING TEMPERATURE, SAID POOL HAVING A FREE SURFACE CONTINUOUSLY INTRODUCING MOLTEN PITCH INTO SAID POOL, CONTINUOUSLY REMOVING FROM BELOW SAID FREE SURFACE OF SAID POOL BY MECHANICAL ENTRAPMENT ALL SOLIDS FORMED IN SAID POOL AND THAT PORTION OF SAID MOLTEN PITCH WHICH HAVE DESCENDED BELOW SAID FREE SURFACE BY THE ACTION OF GRAVITY ON THE POLYMERIZED PARTICLES WHICH HAVE INCREASED IN WEIGHT DURING THEIR PARATIAL POLYMERIZATION, AND SIMULTANEOUSLY PROGRESSING SAID REMOVED SOLIDS AND PARTIALLY POLYMERIZED PITCH ALONG AN UPWARDLY INCLINED PATH, WHILE PERMITTING THE UNPOLYMERIZED LIQUID TO FLOW BACK INTO SAID POOL, SAID UPWARDLY INCLINED PATH BEING THROUGH AN ADDITIONAL COKING ZONE WHEREIN SAID PARTIALLY POLYMERIZED PITCH IS FULLY COKED, AND CONTINUOUSLY DISCHARGING FULLY POLYMERIZED PITCH FROM SAID ADDITION COKING ZONE AS COKE PRODUCTS.
 2. AN APPARATUS FOR CONTINUOUSLY PRODUCING COKE FROM PITCH-LIKE MATERIAL WHICH COMPRISES AN ELONGATAED INCLINED ENCLOSED COKING VESSEL; AND INLET POSITIONED AT THE LOWER END OF SAID INCLINED VESSEL FOR RECEIVING HOT MOLTEN PITCH MATERIAL TO MAINTAIN IN SAID LOWER END A POOL OF MOLTEN PITCH HAVING A FREE SURFACE; A COKE OUTLEN FOR COKE PRODUCT POSITIONED AT THE HIGHER END OF SAID INCLINED VESSEL; A VAPOR OUTLET; CONVERYOR MEANS IN SCRAPING RELATIONSHIP WITH THE BOTTOM INTERIOR SURFACE OF SAID VESSEL BELOW SAID FREE SURFACE OF SAID POOL OF MOLTEN PITCH AND EXTENDING FROM BELOW SAID FREE SURFACE OF SAID POOL OF MOLTEN PITCH AND LONG THE LENGHT OF THE INTERIOR OF SAID INCLINED VESSEL AND OUT THROUGH SAID COKE OUTLET, A PORTION OF SAID CONVEYOR MEANS CONTACTING THE BOTTOM AN DLOWER WALLS OF SAID INTERIOR OF SAID VESSEL AND SAID CONVEYOR MEANS SERVING TO COLLECT SOLIDS AND PARTIALLY POLYMERIZED PITCH MATERIAL FROM BELOW SAID FREE SURFACE OF SAID POOL OF MOLTEN PITCH IN SAID INLET END OF THE INCLINED VESSES, WHEREBY SAID PARATIALLY POLYMERIZED PITCH MATERIAL IS FULLY POLYMERIZED TO FORM COKE, AND TO DISCHARGE SAID COKE THROUGH SAID COKE OUTLET AS PRODUCT; HEATING MEANS POSITIONED ALONG THE LENGTH OF SAID INCLINED VESSEL FOR MAINTAINING SAID PITCH MATERIAL AT COKING TEMPERATURE FOR THE DURATION OF ITS STAY IN SAID VESSEL; AND COKE REMOVAL MEANS POSITIONED AT SAID COKE OUTLET OF SAID VESSEL AND ADAPTED TO DISLODGE COKE PRODUCT FROM SAID CONVEYOR MEANS AS SAID CONVEYOR MEANS DISCHARGES COKE PRODUCT THROUGH SAID COKE OUTLET. 